[init] Fix error message of maxtxfee invalid amount

src/init.cpp

@@ -975,7 +975,7 @@ bool AppInit2(boost::thread_group& threadGroup, CScheduler& scheduler)
     {
         CAmount nMaxFee = 0;
         if (!ParseMoney(mapArgs["-maxtxfee"], nMaxFee))
-            return InitError(AmountErrMsg("maxtxfee", mapArgs["-maptxfee"]));
+            return InitError(AmountErrMsg("maxtxfee", mapArgs["-maxtxfee"]));
         if (nMaxFee > nHighTransactionMaxFeeWarning)
             InitWarning(_("-maxtxfee is set very high! Fees this large could be paid on a single transaction."));
         maxTxFee = nMaxFee;